Our overall objective is to elucidate the macromolecular basis of spermatozoan motility. We shall study the motility of sperm reactivated with ATP after their membranes have been removed with Triton X-100, and attempt to relate the paramenters of the bending waves to the rate of ATP hydrolysis. The mechanism coordinating the active forces between flagellar tubules will be studied by observing the effects of experimental manipulations which produce modified bending waves. We shall direct further attention to purifying our preparations of the ATPase protein dynein, and then study the interaction of dynein with tubulin and with ATP. The interactions of flagellar tubules in isolated preparations will be examined for evidence of dynein cross-bridges between tubules. Using dark-field light microscopy, and electron microscopy, we shall characterize the sliding movements of tubules that are induced by ATP in trypsin-treated axonemes and correlate them with the enzymic and structural changes caused by the trypsin treatment. The tendency of partially disintegrated axonemes and of isolated tubules to coil into helices will be studied under varied conditions. After developing the above techniques with sea urchin sperm, we intend to apply them to the study of maemalian sperm.